Abstract: A monolithic, tandem photovoltaic device is provided having an indium phosphide tunnel junction lattice-matched to adjoining subcells and having high peak current densities and low electrical resistance. A method is provided for relatively low-temperature epitaxial growth of a tunnel junction and a subcell over the tunnel junction at temperatures which leave intact the desirable characteristics of the tunnel junction.
Type:
Grant
Filed:
December 5, 1994
Date of Patent:
September 1, 1998
Assignee:
University of Houston
Inventors:
Mauro F. Vilela, Abdelhak Bensaoula, Alexandre Freundlich, Philippe Renaud, Nasr-Eddine Medelci
Abstract: Apparatus and method for measuring the relative distance between different areas on a remote surface or displacements of a selected area of a remote surface with respect to a measuring apparatus are provided. A laser beam is modulated at an RF frequency and focused on a selected area. The selected area is scanned by movement of a mirror and at each selected area the phase difference is measured. Digital data processing of signals derived from the source and return beams is used to provide high precision. For detecting or measuring vibration or displacement, an analog signal is obtained from a low-pass filter.
Type:
Grant
Filed:
March 19, 1997
Date of Patent:
April 7, 1998
Assignee:
Systems & Processes Engineering Corporation
Inventors:
Byron G. Zollars, Robert C. Chin, Gary B. McMillian, Tommy C. Cruce, William H. Hallidy
Abstract: A method for completing and increasing the production rate from a cased well which may produce solids through perforations during production is provided. A gravel pack screen is placed in the well along with equipment in the tubing string to control flow from inside to outside the tubing below a production packer. The rig used to place the equipment may then be released from the well. The well is then hydraulically fractured. If the well is producing from a high permeability zone, the hydraulic fracture is preferably formed with the tip screen-out technique. The method can also be used in a well already containing production tubing without moving a rig on the well to remove the tubing from the well and can be used in a well not yet perforated by adding tubing-conveyed perforating apparatus below the screen.
Abstract: A three-terminal non-volatile ferroelectric/superconductor thin film field effect transistor (FsuFET). The FSuFET is used as a non-volatile memory storage device that provides two static states and four transient states. The FSuFET includes a superconducting film epitaxially grown on a substrate layer. A ferroelectric thin film is then epitaxially grown on the superconducting layer to form the gate of the FSuFET. A drain electrode and a source electrode are then contacted to the superconducting film on either side of the ferroelectric gate. In static mode, the two polarization states of the ferroelectric gate correspond to the binary "0" and "1" states, which are switched by applying a voltage pulse of sufficient magnitude. In transient mode, the four states depend upon the polarization state of the ferroelectric gate and the conductive state (superconducting or non-superconducting) of the drain-source channel.
Abstract: Bamboo molding or trim is provided from the interior of bamboo culms. The bamboo is divided into pieces which may be laminated to form workpieces from which the molding or trim is formed. Selected cross-sections, spindles and other forms are provided. The bamboo may be treated for resistance to decay or to increase dimensional stability.
Abstract: A method and apparatus for producing direct reduced iron using a melter-gasifier and two reduction reactors. In the first reduction reactor, iron ore is prereduced using a reducing gas from a melter-gasifier. This prereduced iron ore is fed into the melter-gasifier to produce pig iron. A secondary reducing gas comprising hydrogen and carbon monoxide is withdrawn from the first reduction reactor and is reacted with water to produce carbon dioxide which is subsequently removed to produce a tertiary reducing gas that is used in the second reduction reactor to produce direct reduced iron from iron ore.
Type:
Grant
Filed:
September 15, 1995
Date of Patent:
October 14, 1997
Assignee:
HYLSA, S.A. de C.V.
Inventors:
Ricardo Viramontes-Brown, Juan Antonio Villarreal-Trevino
Abstract: Pallets for storage or movement of goods are provided having bamboo members. Split bamboo forms cross-members and successive layers as part of the two major surfaces of pallets. Bamboo culms are used for beams of a pallet or as components in a post-type structure. Frames of split bamboo may be fastened and removed from beams or posts of bamboo to allow more compact movement of pallets not in use. Elongated posts of bamboo culms may be used to join individual pallets for multi-deck pallets.